80gsm plain paper not feeding- Epson L360

Check the printer specs. Epson top load desktop (except wide format) printers have always left something to be desired beyond medium-weight papers. For example, I can put 27lb premium paper in most Epsons, but I would have to double-check the specs for my 90lb cardstock (in contrast, I know my monochrome and color lasers can handle it, but an inkjet printer might struggle). The L310 uses the cheaper XP mechanism, which is one of the mechanisms with some limitations.

If you check the specs, it confirms this has a weaker XP mechanism because it stops at 75gsm (50lb). I know where this comes from: People who know they can push some laser printers marginally. Yes, I can make my color laser with heavy paper, but ONLY in the bypass feeder, and no double-sided prints. While you can run heavy stock though a lot of steel frame laser printers with little to no plastic structural parts with this paper, you can't do it on these top-load Epsons. If they say it's limited to 75gsm/50lb paper, it's borderline beyond that, and they are saying it is because this mechanism is prone to being damaged if you try your luck and lose. If you want to print on heavy paper regularly, you need a color laser like the Lexmark CS series or a Color ImageCLASS with the ability to do it natively.